Burglar-alarm



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BURGLAR ALARM.

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YBURGrLAR ALARM.

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llNiTED STATES PATENT EEicE.

ARTEMAS M. HUNGERFORD AND )VILLIAM )WESLEY BOTT, OF MAITASKA,

KANSAS.

BURG LAR-ALARM.

SPECIFICATION forming part of Letters Patent No. 555,810, dated March 3, 1896.

Application filed September 25, 1895. Serial No. 563,649. (No model.)

To. all whom t may concern:

Be it known that we, ARTEMAS M. HUNGER- FORD and WILLIAM WESLEY Borr, citizens of the United States, residing at Mahaska, in the county of )Vashington and State of Kansas, have invented a new and useful Burglar- Alarm, of which the following is a speciiication.

Our invention relates to a burglar-alarm adapted for use in connection with doors and windows; and the objects in view are to provide simple and efficient means for throwing the alarm into and out of operative position; to provide means for communicating motion from a rotary part to a locking device,whereby the train of gear for communicating motion from the actuating-spring to a hammer is released; and, furthermore, to simplify and improve the construction and arrangement of the actuatingspring, gearing, and hammer to avoid straining and cause the bell to be sounded positively when the mechanism is released.

Further objects and advantages of this invention will appear in the following description, and the novel features thereof will be particularly pointed out in the appended claims.

In the drawings, Figure l is a perspective view of an alarm mechanism embodying our invention applied in the operative position to a window-sash. Fig. 2 is a front view of the same with the gong omitted. Fig. 3 is a vertical central section. Fig. 4; is a rear view. Fig. 5 is a front view of the improved alarm mechanism applied in the operative position to a door. Fig. 6 is a partial vertical section of the same, the gearing for communicating motion to the vhammer being shown in side view. Fig. 7 is a detail view of the shifting device detached, the same being viewed from the rear side. Fig. 8 is a rear view of the gong and the hammer arranged in operative position with relation thereto.

Similar numerals of reference indicate corresponding parts in all the figures of the draw ings.

l designates a base plate provided with means, such as screws 2, for attachment to the object, whether a window or door, by which the alarm mechanism is carried, and

extending perpendicularly from the plane of said plate is a post 3 for the gong 4. The post 3 is rotatably mounted in a bearing in the plate and forms an arbor, to which is attached the actuatingespring 5. The other end of this actuating-spring is attached toa gear G, (see Figs. 3 and 4,) which carries a ring 7 to form' a casing for the spring, a removable disk S being secured to the rear end of the arbor to close said casing. Meshing with the gear is a pinion 9, (see Fig. 4,) the spindle of which carries a spur-wheel 10, (see Fig. 2,) meshing with a spur-pinion ll (see Figs. 2 and 3) loosely mounted upon the arbor in front of the plate. Between said spurpinion and the plate, or at any other convenient point upon the arbor, is permanently fixed a ratchet-wheel l2, (see Figs. 2 and 3,) with which engages a springactuated pawl 13 to prevent backward rotation of the arbor, and secured to and rotatable with the spur pinion ll is a second ratchet-wheel, 14, with which engages a dog 4these pivotal heads are thrown out suiiiciently to come in contact with the surface of the gong, but being pivoted they are adapted to yield when brought into contact therewith. The centrifugal force produced by the rotation of the hammer throws the heads outward, and the rebound caused by contact with the gong repels the heads, whereby a rapid succession of strokes is applied by each head to the gong during the rapid rotation of the hammer.

The main gear, which is actuated by the spring, is normally held from rotation by means of a locking-arm 1S pivoted to the plate and having a nose 19 to engage one of a series of stop-shoulders formed on the ring carried by said gear. These stop-shoulders are are ranged at intervals equal, in the construction illustrated, to a quadrant, whereby, when the locking-arm is disengaged from one stopshoulder and is allowed to return immediately to its normal position the gear moves through a quarter-circle before it is again stopped, and the impulse thus imparted to the hammer causes it to rotate after the gear ceases to rotate. This allows movement of the hammer upon the arbor, and the communication of motion thereto through pawl and rachet mechanism avoids the strain of the apparatus when the movement of the main gear is suddenlychecked by the engagement of the locking-arm with one of the stop-shoulders. The locking-arm is held normally in engagement with the ring of the gear by means of a spring 20, and arranged at the free end of the lockin g-arm is an elongated opening or slot 21 for engagement by a stud 22 on the extremity of a connecting-rod 23.

Thus far the construction of the alarmmechanism is common to both forms illustrated in the drawings; but in order to apply the device to a window whereby the lockingarm may be disengaged from the lockingshoulders when the window is moved, we employ a rotary member or operating-wheel 24E mounted upon a switch 25 fulcrumed upon the base-plate l, as shown at 2G. This rotary member or operating-wheel is provided with a soft or yielding rim or periphery 27, preferably of rubber or its equivalent, for contact with the frame of thewindow, and the lower end of the conneetin g or trip rod 23 is pivotally connected to the rotary member, whereby when motion imparted to said member by the movement of the sash, the rim of the member being in contact with the frame of the window, the rod is moved to draw the locking-arm out of engagement with the main gear of the mechanism and thus release the same. Said switch is held in the desired position, with the rotary member either in or out of contact with the frame, by means of seats or notches 28 on the plate l, with one of which the extremity of the lever is adapted to be engaged, said switch being of spring-metal.

In applying the improved alarm mechanism to a door a slightly different arrangement of parts is necessary, and in the construction illustrated in the drawings we employ the knob 29, of the ordinary construction, as the rotary member from which motion is received to release the alarm mechanism, a clamp 30 being attached to the shank of said knob, to which the lower extremity of the connecting or trip rod 23 is pivotally connected. In this form oi the device we also employ a switch 3l consisting of a guide-plate 32 having an opening 33 through which the trip-rod 23 extends, the shank 34 of said guide-plate extending through a transverse slot 35 in a loop or keeper 36 forming a part of the plate. The shank of the guide-plate terminates at its outer end in aknob or head 36a, by which the plate may be moved laterally to throw the stud at the upper end of the trip-rod into or out of engagement with the opening or slot in the locking-arm, and said plate is secured at the desired point, to maintain the trip-rod in engagement with the locking arm or knob, by means of depressions or notches 39 and 40 at the opposite extremities of the slot in the keeper.

From the above description it will be seen that we employ simple and efficient switch mechanism to throw the alarm mechanism into or out of operative position, and when in operative position the partial rotation of the rotary member communicates motion to the locking-arm and thereby releases the gear which is actuated by the spring. The immediate release and consequent checking of the movement of the rotary member does not immediately check the rotation of the gear, for the reason that the stop-shoulders carried by the gear for engagement by the locking-arm are arranged at such intervals as to allow a greater or less motion after the locking-arm is in operative position. It will be seen, furthermore, that when the movement of the main gear is checked by the engagement therewith of the locking-arm the impulse previously imparted to the hammer causes a further rotation of the latter until it is checked by friction caused mainly by the contact of the heads with the gong. Thus the gong is sounded after the gearhas been cheeked, and, therefore, the energy stored in the spring is not unnecessarily expended.

The gong is provided at its center with an angular opening 4l for engagement with a squared shoulder 42 on the arbor, whereby the spring may be wound by turning the gong, the latter being held in engagement with said shoulder by means of the thumb-nut 43.

In order to increase the eiii'ciency of the hammer and render more positive the strokes of the heads thereof, we provide the interior of the gong with a projection i4 arranged in the path of the pivotal hammer-heads, wherebythe heads come in contact with this proj ection instead of the inner surface of the gong and are then thrown back to prevent cheeking the movement of the hammer. The heads are returned by centrifugal force to their extended or striking position.

Various changes in the form, proportion, and the minor details of construction may be resorted to without departing from the spirit or sacrificing any of the advantages of this invention.

Having described our invention, what we claim isl. In a burglar-alarm, the combination of a rotary arbor provided with means for preventing backward rotation, amain gear concentric with the arbor, an actuatingspring connecting the arbor and gear and adapted to impart rotary motion to the latter, a rotary hammer, connections between said gear and the hammer including pawl-and-ratchet mechanism to allow rotation of the hammer after the motion of the gear has ceased, and

IOO

IIO

a gong arranged in the path of the hammer, substantially as specified.

2. In a burglar-alarm, the combination of a rotary arbor provided with means for pre venting backward rotation, a main gear concentric with the arbor, an actuating-spring connecting the arbor and gear and adapted to impart rotary motion to the latter, a hammer loosely mounted upon the arbor, connections between said gear and the hammer including a pawl and ratchet to allow rotation of the hammer after the motion ci' the gear has ceased, and a gong fixed to the arbor and adapted to be turned with the arbor to wind the spring, substantially as specified.

8. In a burglar-alarm,the combination with alarm mechanism including an actuatingspring and a gear adapted to receive motion threfrom, of a locking-arm, stop-shoulders carried by said gear and adapted to be engaged by the lockingarm to check the rotation of the gear, and a rotary member connected with the locking-arm to disengage the latter from the stop-shoulders to release the alarm mechanism, substantially as specicd.

4. The combination with an automatic alarm mechanism, of a locking-arm normally and yieldingly held in engagement with a rotary part of the alarm mechanism to prevent movement thereof, a rotary member operatively connected with the locking-arm and adapted when turned to disengage the latter and release the alarm mechanism, and a switch mechanism for throwing the rotary member into and out of operative contact with 3 5 a window-frame, substantially as specified.

5. The combination with an alarm mechanism, of a rotary member, a pivotal switch can rying the rotary member and adapted to be moved to throw the rotary member into and 4o out of operative position with relation to a window-frame, a trip-rod connecting the rotary member with the locking-arm, and means for locking the switch in the desired position, substantially as speciied.

6. The combination with an alarm mechanism, of a lockingarm for preventing motion of the alarm mechanism, a rotary member, a pivotal switch carrying the rotary member, a trip-rod connecting the rotary member with 5o the locking-arm, and seats arranged in the path of one extremity of the switch and adapted to be engaged thereby to secure the rotary member in the desired position, substantially as spcciiied.

In testimony that we claim the foregoing as our own we have hereto affixed our signatures in the presence of two witnesses.

ARTEMAS M. HUNGERFDRD. WILLIAM WESLEY BOTT.

Vitnesses:

J. L. NAYLER, W. C. PARKER` 

